Well, I would wrap the netscape binary in a shell
script that nukes the cache when netscape quits.
If netscape is not run in the background, but the
script is, when Netscape exits, the script will
continue to execute. At this point, insert your
code to kill the cache and you're fine. Since
each user starts their own copy of the script you
can simply check the uid and get only the user's
cache.
Adam McClure